Die-stock.



H. W. OSTER & W. J. MACAK.

DIE STOCK.

APPLICATION FILED MAY 16, 1912.

Patented Dec. 23, 1913.

III!

NTTED STATES PATENT @TBTIQE.

HERMAN Vi OSIER AND WILLIAM J. MAOAK, 0F CLEVELAND, OHIO, ASSIGNOES TO THE OSTER MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

DIESTOCK.

Specification of Letters Patent.

Patented Dec. 23, 1913.

Application filed May 16, 1912. Serial No. 697,610.

To all whom it may concern:

Be it known that we, HERMAN W. Osrnn and I VILLIAM J. MAoAx, citizens of the United States, and residents of Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Die-Stocks, of which the following is a full, clear, and exact description.

The object of this invention is to provide a practical and eiiicient die stock of reasonable first cost, which is adapted to cause such slow recession of the dies that they will cut a tapered thread on pipe or other cylindrical work.

The present invention relates entirely to the novel means for causing such slow recession of the dies; and said invention comprises the employment of a ring which is rotatable upon but has no longitudinal movement with respect to the work holder, and t0ggles-0ne associated with each die, one link of each toggle being pivotally connected with said ring and the other link being pivotally connected with a part which is rigid with the associated die, together with guide arms, one for each die, fixed to the die carrier and engaging and guiding the pivot which joins the two links of the associated toggle.

In the drawing, Figure 1 is a central longitudinal sectional view of a die stock embodying the invention; and Fig. 2 is a front end view thereof partly broken away.

The work holder 1 which is of familiar construction, being a built-up member of tubular form so that the pipe or other cylindrical piece of work to be threaded may be passed through it. It is provided with means, as, for example, radially movable clamping pins 10 and a rotatable cam plate 12 for operating them, by which said work holder may be clamped upon the work to be threaded.

The die holder 2 is likewise tubular; and it is capable of moving rotatably and longitudinally relative to the work holder. In the construction shown the die carrier has its rear end externally threaded so that it may be screwed into the internally threaded work holder; wherefore as the die carrier is turned relative to the work holder it will move longitudinally relative thereto at such rate as will be determined by the pitch of the engaging screw threads.

At the front end of the die carrier is an outwardly extended flange 2 which is provided with a plurality of pairs of forwardly projecting ribs 2, 2 between which are radial guideways for the dies or chasers 3. Each of these dies in the construction shown is secured immovably in a die case 5 which slides against the front face of the flange 2, and has laterally projecting ribs 5 which enter grooves in the approximate faces of the two ribs 2*, 2. Each die abuts at its outer end against a shoulder 5 on the die case and it is held in the case by the overhanging gibs 5.

4 represents a ring which is rotatably mounted on the work holder, and is held against longitudinal movement thereon. In the specific construction shown there is an annular groove 1 in the work holder, and into this project pins 4 which screw through the ring 41.

Associated with each die case is a toggle comprising links 6 and 7 which are pivoted together by means of a pivot pin 8. Each link 7 is pivoted to ears 4P on the ring I. The front end of the link 6 is pivotally connected to rearwardly projecting ears 5 on the associated die case.

There are guide arms 2 which are rigid with and project rearward from the flange 2 of the die carrier, and in each of these arms is a slot 2 which is set at an inclination to the axis of the tool. The pivot pin 8 of the associated toggle projects into and slides in the slot 2 of the associated arm 2*. When, now, the die carrier is screwed into the work holder, as it is when the dies are cutting a thread, these pins 8 will slide relatively forward in said inclined slots 2, and

this will cause the movement outward from the axis of the tool of the front ends of the links 6, and at such rate as to cause a proper receding movement of the die cases 5.

Having described our invention, claim 1. In a die stock, the combination of a tubular work holder, a tubular die carrier which is movable radially and longitudinally with respect to the work holder, a ring which is rotatably mounted upon the work holder but is held against longitudinal movement thereon, dies radially movable upon the die carrier, guide arms fixed to said die carrier, and a toggle associated with each die and guide arm, one toggle link of each toggle being pivoted to said ring, and the other toggle link being pivotally connected with a part which is rigid with the associated die, and the pivot between said toggle links being in engagement with the associated guide arm.

2. In a die stock, the combination of a tubular work holder, a tubular die carrier which is movable radially and longitudinally with respect to the work holder, a ring which is rotatably mounted upon the work holder but is held against longitudinal movement thereon, die oases radially movable in guide ways on the front end of the die carrier, guide arms projecting rearward from the die carrier, each having an inclined slot, a toggle associated with each die case, one link of each toggle being pivotally connected with the associated'die case, and the other link of the toggle being pivotally connected with said ring, and the pivot which connects the two toggle links being movable in the inclined slot in the associated arm.

In testimony whereof, we hereunto afiix our signatures in the presence of two witnesses.

HERMAN W. OSTER. WILLIAM J. MACAK. itnesses E. L. THURs'roN, A. J. Henson.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

